Medically Reviewed by Melinda Ratini, DO, MS on December 20, 2020 How Much Do You Need? 1/11 If you eat a balanced diet, it’s pretty easy to get enough. Adult women (who aren’t pregnant or breastfeeding) need 75 milligrams of vitamin C per day; men, 90 milligrams. A mere 1/2 cup of raw red bell pepper or 3/4 cup